I think the person in the mirror has reached the top of the knowledge limit and needs someone that is an expert to move me to a higher level. 

I also don't use them on my personal, but that personal choice. 

The best advice on this topic, in my opinion, comes from 2 books:How to win friends and influence peopleNever eat aloneI am also looking for brokerages to work with or even experienced shadow / intern for to gain experience and additional knowledge.

@Ibrahim AtoumIf you're starting house hacking at 20, focus on building your knowledge and financial readiness.

The best way to estimate expenses is experience and knowledge of your specific asset type and market.For vacancy, that will depend on your market and the quality/desirability of your type of unit.

Then, as you buld knowledge & experience you can do bigger projects.3) The two above strategies can build funds to invest in rentals.

However, I have very little knowledge about getting started.

One of the best things you can do to boost your forum, podcast, and book knowledge is to get out to real estate investing meetups in your area.

If you desire to get it by all means go for it - knowledge is power - but thats knowledge you pay for that may or may not pay off for you.  

Exceptionally knowledgeable, very professional, and service oriented.